[sdiy] PIC help

[Csaba Zvekan]

Hi Scott,

As Terry mentioned earlier I would go with the newer flexis (32-bit) 
microcontrollers from Freescale . They are very cheap plus they come with a 
fully working compiler (Code Warrior) totally free of charge and not 
crippled. As for the display I recommend my little "two wire LCD" project. 
It would free up a lot of pins on your MCU.
Check out the project at 
http://www.csaba.ch/index.php?option=com_content&task=view&id=22&Itemid=30

Regards

Csaba

----- Original Message ----- 
From: "Scott Juskiw" <scott at tellun.com>
To: "sdiy DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Monday, June 08, 2009 3:28 AM
Subject: [sdiy] PIC help


> For the third time in as many years I'm making an attempt to venture  into 
> PIC development because all the new synth modules I want to build  would 
> benefit from a digital controller of some sort. I spent most of  the 
> weekend going over the sdiy archives and microchip website but  sadly, am 
> once again flummoxed by the options and am wondering if  someone can 
> answer a few newbie questions.
>
> Maybe it would help if I explain my situation. My current project is a 
> programmable filter bank with the following requirements:
>
> a. 10 (at most) analogue inputs for reading pots, 10 bit ADC would be 
> fine
> b. a few digital inputs for reading switches and pushbuttons
> c. 24 analogue outputs to control filter frequency, Q, gain etc, 12  bit 
> DAC would be fine
> d. EEPROM for storing presets
> e. ability to hook up an LCD display (2 line by 40 character or smaller)
>
> 1. What programmer/debugger do you use or recommend? I don't want to 
> build one, or get some third party box. I've narrowed the choices down  to 
> either the PICkit 3 ($70) or MPLAB ICD3 ($220) and am wondering if 
> there's any significant advantage to the ICD3 that makes it worth  being 
> 3X as much as the PICkit 3.
>
> 2. How do you decide which PIC chip to use? I know some of you are  using 
> the dsPIC33FJ128GPxxx series (Tom, Seb, Eric) and I'm more than  happy to 
> follow your lead, but it might be overkill for my needs. But  they aren't 
> too expensive, should I just go with the flow and use the  latest and 
> greatest chips?
>
> 3. Some of the dsPIC chips have a built-in 16-bit DAC but it appears  to 
> be best suited for two channels of audio, not for 24 channels of  control 
> voltages. Would I be better off using an external DAC to get  24 analogue 
> outs and avoid the internal DAC?
>
> 4. If using an external DAC, is there any advantage to using one DAC  with 
> lots of multiplexing to get 24 outputs vs. using several 8- channel DACs 
> (e.g. TLV5610)?
>
> 5. It seems that dsPIC chips don't have enough built-in EEPROM to  store 
> all the info I want for the presets. Is it best to avoid trying  to max 
> out the internal EEPROM and use an external EEPROM? (I see that  Seb has 
> hooked up an EEPROM to his Digi-Mod.)
>
> 6. What do you recommend for an LCD display (2x40 character or less)  that 
> would be simple to hook up to a PIC? Do these things have some  kind of 
> common interface (SPI)?
>
> Thanks for your help and guidance.
>
>
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